This invention relates to a testing method for use in determining whether a batting member utilizable in a competitive sporting game complies with predetermined performance standards. The invention also relates to an associate apparatus utilizable in carrying out the method.
Performance standards on baseball and softball bats have been in effect since first proposed over twenty years ago. The standards were introduced to limit the hit ball speeds produced by these bats in an effort to insure the safety of the players and the integrity of the game. The standards were originally intended to insure that metal bats did not perform significantly better than the wood bats that were historically used. When high-performing composite (mainly carbon-fiber) bats were subsequently introduced, they were subject to the same standards, but it was found that these standards had to be generalized in order to account for the special characteristics of the new bats.
It was soon realized, however, that the performance of composite bats improved with usage. Each ball impact experienced by these bats tended to delaminate or otherwise damage the carbon fibers, causing the bat to become more elastic and more powerful. These bats could therefore be found compliant with the existing standard when they were tested before being used to hit balls, but could become non-compliant (too powerful) if tested after sufficient usage.
In addition to the increase in performance of composite bats arising from usage, the performance of these bats can be artificially increased. This can be done by pushing and pulling the bat 24 between rollers 26 and 28 (FIGS. 1 and 2) compressed onto it, or by simply impacting the bat with balls or other objects. Another way to increase the performance of a composite bat is to shave out material from the inside of the bat's barrel.
In order to take these performance increases into account, some baseball and softball organizations proceeded to adopt an “automated break in” (ABI) procedure into the testing procedures. In these protocols, performance measurements on a tested bat are alternated with “breaking-in” procedures using a rolling device 20 (FIG. 1). One such protocol is the following. After an initial performance measurement, a bat's elasticity is measured by compressing the bat 24 a specified distance between a pair of cylindrical sections 30 and 32 (FIG. 3). The bat is then rolled by cylinders 26 and 28 compressed into it a specified distance. A second elasticity measurement is then made at the same specified distance as before, followed by a second rolling at a greater distance into the bat. This procedure continues until the bat's elasticity has decreased by a specified percent (typically 10%). The bat's performance is then measured again, and this procedure is continued until either the bat's performance exceeds a specified limit or the bat exhibits visible damage. If the damage occurs first, the bat is considered compliant, but if the performance limit is exceeded first, the bat is not considered compliant. The hope is that similar damage on a compliant bat caused by impacts during a ball game could then be observed, and the bat could be then be removed from play before it became non-compliant.
The above barrel rolling machines typically use two nylon cylinders of diameter between 1.5″ and 3″. These are set within a fixture that can press them into a bat barrel in increments of 0.0125″. At least one of these rollers can be rotated within the fixture so that the bat barrel can be rolled between them. A typical barrel-rolling device is shown in FIG. 1 and illustrated in FIG. 2. The corresponding elasticity measurement device is illustrated in FIG. 3.
There are a number of serious problems with this rolling ABI protocol. It is complicated and time-consuming to use. It is not precise, accurate, controllable, or repeatable. It adds an element of influence by the tester to the otherwise accurate performance measurements. It requires the tester to determine the degree of compression and to determine visually if and when damage occurs anywhere on the bat barrel. The result of a test can depend on details of the rolling procedure not precisely controllable, such as the exact compression distance, the rolling speed, and the bat's alignment during the rolling. The rolling cannot be accurately performed on bats with tapered barrels. Another serious problem is that a bat could show damage when rolled to a sufficient distance, but not when impacted by balls. Such a bat could become non-compliant (too powerful) because of impacts with balls, but would not be removed from play because it would not display visible damage arising from these impacts.
The use of such a rolling device to execute automated break-in is therefore problematic. A typical protocol calls for roller compression distance increases of 0.0125″, and bat rotations of 45°, etc., but the rolling devices are not capable of providing such precise values. Also, the rolling itself is a broad and harsh procedure that lacks adequate controls. The procedure is inefficient because it softens the bat everywhere and not in the way that ball impacts soften it. Also, the elasticity measurements are executed with two opposing cylindrical sections instead of with a spherical-like section at a single area, which is the way a struck ball experiences the elasticity of a bat. The following description will teach how all of these problems can be overcome by using different automated break-in equipment. To be specific, references herein are to baseball/softball bats, but it is understood that the same type of equipment and methods can be used to break in other sports equipment.